imm atom_based nanotechnology workshop, 19 th january 2011, arcetri (fi), italy the network on...
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IMM
Atom_based Nanotechnology workshop, 19th January 2011, Arcetri (FI), Italy
The network on graphene at IMM
OUTLINE
• The IMM graphene research network• The agreement with Industry • Competences and acquired know how at IMM Agrate (MDM)• Competences and acquired know how at IMM CT
Slide 1/15
Istituto per la Microelettronica e Microsistemi
IMM
Atom_based Nanotechnology workshop, 19th January 2011, Arcetri (FI), Italy
Bologna
Roma
Napoli
Lecce
Catania
Milano
The graphene research network at IMM
Graphene like materials (silicene, germanene, …) Memories and logics
Advanced characterisation & sensors See V. Morandi, R. Rizzoli
materials fundamentals & devices (Rf, power, …)
Slide 2/15
IMM
Atom_based Nanotechnology workshop, 19th January 2011, Arcetri (FI), Italy
Bologna
Roma
Napoli
Lecce
Catania
Milano
The graphene research network at IMM
Graphene like materials (silicene, germanene, …) Memories and logics
Advanced characterisation & sensors See V. Morandi, R. Rizzoli
materials fundamentals & devices (Rf, power, …)
Slide 3/15
IMM
Atom_based Nanotechnology workshop, 19th January 2011, Arcetri (FI), Italy
Bologna
Roma
Napoli
Lecce
Catania
Milano
The graphene research network at IMM
Graphene like materials (silicene, germanene, …) Memories and logics
Advanced characterisation & sensors See V. Morandi, R. Rizzoli
materials fundamentals & devices (Rf, power, …)
Slide 2/15
IMM
Atom_based Nanotechnology workshop, 19th January 2011, Arcetri (FI), Italy
Bologna
Roma
Napoli
Lecce
Catania
Milano
The graphene research network at IMM
Graphene like materials (silicene, germanene, …) Memories and logics
Advanced characterisation & sensors See V. Morandi, R. Rizzoli
materials fundamentals & devices (Rf, power, …)
The industrial cluster
3Sun
Slide 2/15
IMM
Atom_based Nanotechnology workshop, 19th January 2011, Arcetri (FI), Italy
Bologna
Roma
Napoli
Lecce
Catania
Milano
The graphene research network at IMM
Graphene like materials (silicene, germanene, …) Memories and logics
Advanced characterisation & sensors See V. Morandi, R. Rizzoli
materials fundamentals & devices (Rf, power, …)
The industrial cluster
3Sun
Slide 2/15
J.D.P.J.D.A.
J.D.A.
IMM
Atom_based Nanotechnology workshop, 19th January 2011, Arcetri (FI), Italy
IMM-Agrate expertise on ReRAM memory devices Challenge: Resistive Random Access Memory
(ReRAM) in graphene.
EMMA Project-FP6 (1/9/2006-30/11/2009): Emerging Materials for Mass-storage Architectures (contact: Marco Fanciulli and Sabina Spiga)MORE Project 2010-2012 (CARIPLO): Advanced Metal-Oxide heterostructure for nanoscle ReRAM (contact: Sabina Spiga)
Top electrode
Bottom electrode
A
resistive material
Top electrode
Bottom electrode
ReRAM: a large class of emerging non-volatile memory concepts is based on a 2-terminal resistor as a memory
element that can be programmed in a high and low conductive state
Memristor concept introduced by HP
Large interest from worldwide industries on ReRAM for post high-density FLASH and for Flexible
Nonvolatile Memory Applications
Graphene Oxide Thin Films (as switching element) for Flexible Nonvolatile Memory applications H.Y. Jeong at al., Nanoletters 2010, 10, 4381–4386
single layer graphene as electrode on Nb-doped STO substrate for Pt/NiO/graphene nano-ReRAM
graphene
IMM-Agrate expertise up to now: NiO, Nb2O5, TiO2 based metal/oxide/metal thin film- and nanowire-
heterostructures
J. Y. Son et al., ACS Nano 4, 2010, 2655-2658
Slide 3/15
CNR- IMM- Agrate
IMM
Atom_based Nanotechnology workshop, 19th January 2011, Arcetri (FI), Italy
MBE of Si on Ag(110), Ag(111) substratesRef. Aufray et al, Appl. Phys. Lett. 97, 223109 (2010);
Aufray et al, ibidem 96, 183102 (2010)
Option 1: silicene on metals, (in analogy with graphene)
Option 2: encapsulation silicene with 2D hexagonal dielectric lattices
Challenge: Graphene-like materials
graphite-like AlN 2D top lattice
graphite-like AlN 2D bottom lattice
functionalized silicene
Graphene like semiconductors (silicene, germanene) valuable option for active material in Post-CMOS
ditital logic devices and circuits
@ CNR-IMM (Lab. MDM)
• Molecular beam epitaxy apparatus for growth, functionalization amd in situ characterization of graphene like materials
• in situ SPM and spectroscopic diagnostic tools
• dielectric capping for prototypical MOS-like devices
Slide 4/15
CNR- IMM- Agrate
IMM
Atom_based Nanotechnology workshop, 19th January 2011, Arcetri (FI), Italy
Synthesis methodsMechanical exfoliation of highly oriented pyrolityc graphite (HOPG)
High material quality: Low defects density,High mobility
Small sheets;Low production yield
Epitaxial graphene on SiC by controlled graphitisation of the surface at high temperatures (1500 –2000 °C) in inert gas ambient
Large area (wafer scale) sheets on semiconductor substrate
Substrate cost
Can be placed on different substrates:SiO2 , SiC, high-k dielectrics
Chemical exfoliation of highly oriented pyrolityc graphite (HOPG)
High production yield Small sheets;DefectsCan be placed on different substrates:
SiO2 , SiC, high-k dielectrics
growth methods
GRAPHENE at IMM-CT: highlights
More than 30 papers since 2005 by two groups (theory & Exp.)
Slide 5/15
S. Sonde, F. Giannazzo, V. Raineri, and E. Rimini, J. Vac. Sci. Technol. B 27, 868 (2009).S. Sonde, F. Giannazzo, V. Raineri, and E. Rimini, Phys. Status Solidi B, 1–4 (2010) S. Sonde, F. Giannazzo, V. Raineri, R. Yakimova, J.-R. Huntzinger, A. Tiberj, and J. Camassel, Phys. Rev. B 80, 241406(R) (2009).
IMM
Atom_based Nanotechnology workshop, 19th January 2011, Arcetri (FI), Italy
Synthesis methodsMechanical exfoliation of highly oriented pyrolityc graphite (HOPG)
High material quality: Low defects density,High mobility
Small sheets;Low production yield
Epitaxial graphene on SiC by controlled graphitisation of the surface at high temperatures (1500 –2000 °C) in inert gas ambient
Large area (wafer scale) sheets on semiconductor substrate
Substrate cost
Can be placed on different substrates:SiO2 , SiC, high-k dielectrics
Chemical exfoliation of highly oriented pyrolityc graphite (HOPG)
High production yield Small sheets;DefectsCan be placed on different substrates:
SiO2 , SiC, high-k dielectrics
growth methods
GRAPHENE at IMM-CT: highlights
More than 30 papers since 2005 by two groups (theory & Exp.)
Slide 5/15
S. Sonde, F. Giannazzo, V. Raineri, and E. Rimini, J. Vac. Sci. Technol. B 27, 868 (2009).S. Sonde, F. Giannazzo, V. Raineri, and E. Rimini, Phys. Status Solidi B, 1–4 (2010) S. Sonde, F. Giannazzo, V. Raineri, R. Yakimova, J.-R. Huntzinger, A. Tiberj, and J. Camassel, Phys. Rev. B 80, 241406(R) (2009).
BEYOND STATE OF THE ART
First EG on 4H-SiC off axis
Patended substrates
High mobility
IMM
Atom_based Nanotechnology workshop, 19th January 2011, Arcetri (FI), Italy
GRAPHENE at IMM-CT: Highlights
Transfer to substrates: methods and functionalization
Slide 6/15
Silanization of SiOSilanization of SiO2 2
Phosphonization of SiOPhosphonization of SiO2 2
Transfer by Transfer by nanoimprintingnanoimprinting
Few -layers graphene on m etalFew -layers graphene on m etal
IMM
Atom_based Nanotechnology workshop, 19th January 2011, Arcetri (FI), Italy
GRAPHENE at IMM-CT: Highlights
Transfer to substrates: methods and functionalization
Slide 6/15
Silanization of SiOSilanization of SiO2 2
Phosphonization of SiOPhosphonization of SiO2 2
Transfer by Transfer by nanoimprintingnanoimprinting
Few -layers graphene on m etalFew -layers graphene on m etal
CHALLENGES • From nanoscale properties to large area EG on 4H-SiC (150 mm)• Functionalisation (to control the G carrier concentration,
to control the G layer transfer to other substrates)
IMM
Atom_based Nanotechnology workshop, 19th January 2011, Arcetri (FI), Italy
Quantum capacitance and local transport
GRAPHENE at IMM-CT: Highlights
Qdepl
SCM Electronic Module
+ Vg
n+ SiCn+ SiC
n-SiCAeffQscrGraphene
Qdepl
Under the influence of electric field, 2DEG manifests itself as a capacitor, Quantum capacitor.
+ Vg
Gnd
C’q
C’depl
ΔVgr
ΔVdepl
0 .0 0 .5 1 .0 1 .5 2 .01 0
-4
1 0-3
1 0-2
1 0-1
1 0 0
SiO 2
G ra p h e n e
C
(a
.u.)
V g (V )
0.0 0.5 1.0 1.50
5
10
15
20
25
Ae
ff (×1
04 nm
2)
n (×10 1 1 cm-2 )
0 10 20 30 400
100
200
300
l eff (
nm)
n (× 106 m -1)
SiO
SiC
leffAeff
F. Giannazzo, S. Sonde, V. Raineri, E. Rimini, Nano Lett. 9, 23 (2009).F. Giannazzo, S. Sonde, V. Raineri, and E. Rimini, Appl. Phys. Lett. 95, 263109 (2009).
Slide 7/15
IMM
Atom_based Nanotechnology workshop, 19th January 2011, Arcetri (FI), Italy
GRAPHENE at IMM-CT: HighlightsThe role of interfaces on mobility
104
10 5
10 6DG -SiC
SPP
ci
equi
exp10 4
10 5
10 6EG -SiC
cm
2 /Vs
0.5 1.0 1.5
10 4
105
10 6DG -SiO 2
nV g-n0 (×101 1 cm 2 /VS)
Nci_EG=2.5x1011cm-2
23000 cm2V-1s-1
Epitaxial graphene
Slide 8/15
Giannazzo F, Roccaforte F, Raineri V, Liotta SF, Europhys. Lett., 74, 686 (2006)
S. Sonde, F. Giannazzo, C. Vecchio, V. Raineri, E. Rimini, App. Phys. Lett., 97, 132101 (2010)Also selected for publication on Virtual Journal of Nanoscale Science & Technology.
IMM
Atom_based Nanotechnology workshop, 19th January 2011, Arcetri (FI), Italy
GRAPHENE at IMM-CT: Highlights
From thin to fat FET
1 m1 m 60 nm
mnm
60 nm60 nm
mnm
1 m1 m 60 nm
mnm
60 nm60 nm
mnm
Atomic force microscopy
4H-SiC (0001) n+
4H-SiC (0001) n-EG
HSQ PtPt Pt
GateDrainSource
Lg=10m
Optical microscopy
Slide 9/15F. Giannazzo, C. Vecchio, V. Raineri, E. Rimini, submitted
IMM
Atom_based Nanotechnology workshop, 19th January 2011, Arcetri (FI), Italy
-5 0 5 10
0.0
2.0x10-5
4.0x10-5
6.0x10-5
8.0x10-5
VD = 0 V VD = 0.2 V VD = 0.4 V VD = 0.6 V VD = 0.8 V
ID(A)
VG(V)
Transfer characteristicsHole conduction
Dirac point
Output characteristics0V < VD< 10V0V < VG< 14V
STEP = 1V
0 5 100.0
3.0x10-4
6.0x10-4
9.0x10-4
VG = 14 V
VG = 12 V VG = 10 V VG = 8 V VG = 6 V V
G = 4 V
VG = 2 V V
G = 0 V
I D(A
)
VD(V)Transconductance
-2 0 2 4 6 8 10 12 14-4.0x10
-6
-2.0x10-6
0.0
2.0x10-6
4.0x10-6
6.0x10-6
VG(V)
gm(S
)
VD = 0.8 V
VD = 0.6 V
VD = 0.4 V
VD = 0.2 V
VD = 0 V
Ambipolar transport
Electron conduction
GRAPHENE at IMM-CT: Highlights
fat FET characteristics
Slide 10/15
IMM
Atom_based Nanotechnology workshop, 19th January 2011, Arcetri (FI), Italy Slide 11/15
0 10 20 300
1000
2000
3000
eff (
cm2 V
-1s-1
)
Vgs
(V) 0 20 40 60 80 1000
20
40
60
80
100
Fre
qu
en
cy (
%)
l (nm)
first processing end of processing
0 2000 4000 6000 80000
20
40
60
80
100
(cm2V-1s-1)
Mapping distribution
GRAPHENE at IMM-CT: challenges
IMM
Atom_based Nanotechnology workshop, 19th January 2011, Arcetri (FI), Italy
CHALLENGES • Physical model nano- macro properties• New devices architectures
Slide 11/15
0 10 20 300
1000
2000
3000
eff (
cm2 V
-1s-1
)
Vgs
(V) 0 20 40 60 80 1000
20
40
60
80
100
Fre
qu
en
cy (
%)
l (nm)
first processing end of processing
0 2000 4000 6000 80000
20
40
60
80
100
(cm2V-1s-1)
Mapping distribution
GRAPHENE at IMM-CT: challenges
Buried gate
New devices architectures
MIS inversion layer
FLGInsulator
Id
Vg>Vth
MIS inversion layer
FLGInsulator
Id
Vg>Vth
Rdrift
Rsource
CMIS
CMIS
CFLG
Rch,MIS RFLG
Vg
Rc,FLG-SiC
Vd
Rdrift
Rsource
CMIS
CMIS
CFLG
Rch,MIS RFLG
Vg
Rc,FLG-SiC
Vd
(a) (b)
(c)
Vg VgGateSource
Vd
Drain
n-typeSiC
n+-type
p-type
n+-typeFLG
InsulatorVg Vg
GateSource
Vd
Drain
n-typeSiC
n+-type
p-type
n+-typeFLG
InsulatorMIS inversion layer
FLGInsulator
Id
Vg>Vth
MIS inversion layer
FLGInsulator
Id
Vg>Vth
Rdrift
Rsource
CMIS
CMIS
CFLG
Rch,MIS RFLG
Vg
Rc,FLG-SiC
Vd
Rdrift
Rsource
CMIS
CMIS
CFLG
Rch,MIS RFLG
Vg
Rc,FLG-SiC
Vd
(a) (b)
(c)
Vg VgGateSource
Vd
Drain
n-typeSiC
n+-type
p-type
n+-typeFLG
InsulatorVg Vg
GateSource
Vd
Drain
n-typeSiC
n+-type
p-type
n+-typeFLG
Insulator
IMM
Atom_based Nanotechnology workshop, 19th January 2011, Arcetri (FI), Italy
GRAPHENE at IMM-CT: ELECTRON STRUCTURE AND COHERENT TRANSPORT IN CONFINED GRAPHENE
Methodology
Electronic Structure Quantum transport
Ab initio Semiempirical
Density functional
theory, LDA and GGA exchange-correlation functionals, GAUSSIAN and SIESTA
codes
Tight-Binding (TB): single π-orbital Hamiltonian,
further parameterizations based on DFT
Extended Hückel Theory (EHT): real-orbital basis,
parameters from DFT calculations or
experimental data
Transport
Non-equilibrium Green’s functions methods coupled
to Landauer-Büttiker approach
Electrostatics
3D Poisson solver, computational box with
Neumann/Dirichlet boundary conditions
Slide 12/15
IMM
Atom_based Nanotechnology workshop, 19th January 2011, Arcetri (FI), Italy
the simulation approach to transport propertiesPrevious activity overview Computation apparatus: self-consistent transport calculations Atomistic modeling of disorder in graphene based systems: from the single defect/impurity to a finite density of scattering centers GNR-metal junctionEpitaxial GNR on SiC(0001): role of interface statesFocus on defective and functionalized epitaxial GNR Complete device simulation
At CNR-IMM Catania• In house programming codes for
electronic structure and quantum transport based on atomistic semi-empirical Hamiltonians (Extended Hückel and Tight-Binding), NEGF-Poisson scheme
• Full-device simulation for 103 – 107 atoms (in the case of GNRs)
• Atomistic treatment of local alterations in the atomic structure, disorder, etc.
• Multiscale approach (electronic Hamiltonians calibrated or evaluated by first-principles calculations)
GRAPHENE at IMM: Highlights
Slide 13/15
A. La Magna et al, PRB 80, 195413 (2009) I. Deretzis and A. La Magna, Appl. Phys. Lett. 95, 063211 (2009)I. Deretzis et al., J. Phys. Cond. Mat. 22, 095504 (2010)I. Dertzis et al., Phys. Rev. B 81, 085427 (2010)I. Deretzis et al., Phys. Rev. B 82, 161413(R) (2010)I. D. and A. La Magna, accepted Appl. Phys. Lett.
IMM
Atom_based Nanotechnology workshop, 19th January 2011, Arcetri (FI), Italy
IMM - CT • From nanoscale properties to large area (150 mm wafers)• Physical model considering nano-properties for macro-effects• New devices architectures• Functionalisation (to control the G carrier concentration,
to control the G layer transfer to other substrates) • Computational transport properties: multi scale approach
Slide 14/15
IMM - Agrate • Memories and logics in graphene• Graphene-like materials
IMM - Bo • see coming presentations for details
Challenges
IMM
Atom_based Nanotechnology workshop, 19th January 2011, Arcetri (FI), Italy
Thank you for your attention
Catania:
Antonino La Magna*
Giuseppe Angilella**
Ioannis Deretzis***
Raffaella Lo Nigro*
Filippo Giannazzo*
Vito Raineri*
Emanuele Rimini**
Sushant Sonde***
Carmelo Vecchio ****
Agrate:
Marco Fanciulli**
Alessandro Molle*
Sabina Spiga*
Slide 15/15
* Ricercatori CNR di ruolo** Associati*** Post-doc**** Dottorandi
Bologna:
Vittorio Morandi*
Luca Ortolani***
Rita Rizzoli*
Giulio Paolo Veronese*
Alberto Roncaglia*